A survey of 1,500 people conducted for The Information Standard, a body backed by NHS England, found that four in ten have held back from seeing their family doctor despite having symptoms they were concerned about.

In two thirds of cases their condition failed to go away or became worse, with one in five needing a stronger course of treatment because of the delay.

More than half of those who delayed going to the doctor said they had looked up their symptoms online, raising concerns that people are diagnosing and treating themselves rather than seeking the advice of a GP.

Some 55 per cent of people who put off visiting their doctor said they had done so because they thought their symptoms would go away on their own, while 39 per cent said they were worried about wasting their doctor's time.

Ann Robinson, director of public awareness for The Information Standard, which certifies health and care organisations as reliable sources of information, said: "People are delaying their GP visit for various reasons but, regardless of the reason why, our concern is that people are admitting to self-diagnosing and self-treating in the meantime.